1. Field of the Invention
The present invention relates to a rack and pinion mechanism.
2. Description of Related Art
A steering apparatus for a vehicle has a rack and pinion mechanism which converts a rotational force of a steering wheel into a reciprocating motion in a vehicle width direction. The rack and pinion mechanism includes a pinion shaft in which an operating force (rotational force) is inputted and which has pinion teeth and a rack shaft having rack teeth to be engaged with the pinion teeth.
The rack and pinion mechanism also includes a rack guide (pressing portion) slidingly contacting the rack shaft and pressing the rack shaft toward the pinion shaft, and a compressed coil spring biasing the rack guide toward the rack shaft by an elastic restoring force for preventing backlash between the pinion shaft and rack shaft (refer to JP-A-2002-240723 (Patent Document 1). That is, the rack guide constantly presses the rack shaft toward the pinion shaft by the elastic restoring force of the compressed coil spring. Namely, the rack guide presses the rack shaft to the pinion shaft also when the rack shaft is engaged with the pinion shaft in good condition and a center distance between the shafts is suitable.